We’ve already discussed the “Full analysis” and “Blundercheck” analysis functions in the Fritz family of playing programs (Fritz 13, Junior 12, Hiarcs 13, Shredder 12, and Rybka 4). But there’s a third method of analyzing games which we’ve not yet considered. I recently saw a comment in which a user appeared concerned that Fritz only pointed out a user’s errors, and didn’t provide an “attaboy!” for good moves in the analysis modes which we’ve previously explored. My response to that concern is that the “attaboys” are implicit rather than explicit; if Fritz isn’t criticizing a move, then it’s safe to assume that the move was sufficient (at least relatively, given the “Threshold” parameter that’s used in the game’s analysis).

But there is a way to get Fritz’s opinion on every move in a game, as well as to have multiple engines analyze a game in one go. It’s called “Compare analysis”, and it’s the topic of today’s uscfsales.com blog post.

“Compare analysis” was introduced as a means to compare the analysis of multiple chess engines (hence the feature’s name). A user could compare not only the evaluations and preferred best moves of multiple chess engines, but could also compare their relative speeds (in positions evaluated per second). The feature was designed primarily for the use of chess engine developers as a means of comparing their own engine’s performance with that of established programs. One would think that this would consequently not be too interesting a feature for the average chess computer user, but the opposite is true – not only can you have more than one engine analyze the same game after a single “setup” operation, but you’ll also have the game’s every move (outside of opening book moves) analyzed, meaning that you’ll discover not just the mistakes you’ve made, but your good moves as well.

So let’s find out how to subvert this engine programmer tool to our own nefarious purposes as struggling chessplayers…

As always, start by launching Fritz, then open the game list for the database in which your “analysis candidate” game resides. Single-click on the game to highlight it in the list, click the “Database” tab, and look for the “Compare analysis” button:

Click this button to display the “Compare analysis” dialogue:

We’ve seen some of these parameters before in our discussions of Fritz’s other analysis modes, so I won’t repeat the material in detail here. I will give you a couple of recommendations, though. Chess engines tend to work better and give better analysis when you analyze the moves for both players, so do select “Both”. Also, when you’re using the “Time” setting, keep in mind that you’re going to have multiple engines analyze your game. So if a setting of “60” means that it typically takes the software, say, ninety minutes to analyze a game when you’re using the other analysis modes, you’ll need to multiply that ninety minutes by the number of engines you’re using in “Compare analysis” mode. For example, having three engines analyze this one game will take about the same amount of time as having one engine analyze three games in the other analysis modes.

And, as we’ve seen before, the “Time” and “Depth” settings are mutually exclusive – you can use one, not both. “Depth” is useful for the occasions when you want to have an engine analyze a game “in the background” when you’re using your computer for other tasks, so that the specific depth will always be reached no matter how long it takes to achieve it. “Time” is best for the occasions when you’re going to just totally turn your computer over to the chess engine (overnight while you sleep, for example).

To make “Compare analysis” work, we’ll need to select the engine or engines which we’ll use to analyze the game. To add an engine, click the “New” button:

…and you’ll get the dialogue shown above. Scroll through the list of engines to select one you want, set the hashtable size (as we’ve previously discussed), and set any engine parameters you wish to use (by clicking that button to display that dialogue).

This brings us to another tip: if you’re going to have more than one chess engine analyze the game, it’s useful to have the software display the analysis in different colors for different engines. Click the “Variation color” button to display the Windows color palette and choose the color in which the engine’s analysis will appear in the gamescore. After you select a color and click “OK”, you’ll see the band under the “Variation color” button display the color you’ve chosen:

Click “OK” after you’ve made your selections, and the engine will appear in the list. Repeat the process, choosing a different variation color for each engine, until you’ve selected all the engines you wish to use:

If you decide to change some details for an engine’s settings, highlight it in the list and click “Edit”.

If you want to completely remove an engine from the list, highlight it and click “Delete”. Note that this does not delete the engine from your hard drive – it just removes the engine from the “Compare analysis” list.

There’s one more setting which is unique to this dialogue that we need to mention: the “Node count” toggle. Selecting this will display the number of positions each engine analyzed as part of their displayed evaluations. This is useful for users who want to compare the relative speeds of various engines, but otherwise isn’t terribly useful. I seldom use it, but do please feel free to play around with it.

After your selections are complete, click “OK” and let ‘er rip! If you hang around to watch, the Fritz GUI will load the first engine you selected and it will begin to analyze the game starting with the final position and working backwards. When it reaches the “Last book move” (as we’ve seen previously), the GUI will unload the first engine, load the second engine, and the process will repeat.

When it’s all said and done, you’ll wind up with a gamescore which looks something like this:

Click on the picture for a larger view

For each move of the game (except “book” moves in the opening) you’ll see analysis from all of the chess engines you selected. You can see from the illustration why I recommended that you color each engine’s analysis in a separate shade: it makes it easier to differentiate between them.

By the way, the evaluation for each game position (given after each “text” move, that is, the moves that were actually played in the game) are provided by the last engine to analyze the game, which will be the last engine listed in the “Compare analysis” dialogue. So if you’re going to use some “speculative” engine parameters (for example, change Junior 12’s settings to look for [possibly unsound] sacrifices), you’ll probably want to add such an engine at the top of your “Compare analysis” listing, leaving the last listed engine at its “default factory settings”.

You can scroll up and down the gamescore to compare the moves played in the game with the moves recommended by each engine. You can also compare the numeric positional evaluation of an actual move with the evaluations given at the end of the recommended variations, to look for improvements. In this way, you’ll see not only criticism of your moves, but also get the “attaboys!” for the good moves you’ve played.

Now a couple of reminders:

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